I hope this doesn't sound like a pitch but I'm curious what other folks know about this. I know other professionals pay good money for Facebook clicks and I accidentally got one for free. 

I posted an ad for something to facebook marketplace and I get a response within a day or two. After the deal was done the buyer asked me what marketplace was and how I knew about it. I was confused because I posted the for sale ad on marketplace, and then they messaged me through marketplace to buy the thing. How did they not know about marketplace if that is how they found me?

I found out they had done a search for something similar to what I was selling and then they were on facebook. Facebook served them an ad for my specific listing and it didn't cost me anything. They clicked the ad and then I guess it brought them into marketplace or something I'm really not sure....

Maybe this is already known about, but I feel like I stumbled upon a gem. If I'm wrong don't hesitate to tell me!